Can I take Danazol and Metformin together?

Why this happens

Danazol is a synthetic steroid that can cause 'insulin resistance'. This means it makes your body's cells less responsive to insulin and can increase the amount of sugar your liver produces, which directly opposes the blood-sugar-lowering effects of metformin.

What you should do

You should monitor your blood sugar levels more frequently than usual. If you notice your readings are consistently high, or if you experience symptoms of high blood sugar (such as feeling very thirsty, needing to urinate more often, or blurred vision), contact your doctor. They may need to adjust your metformin dose while you are taking danazol.

Important precautions

Pregnancy

You must not take danazol if you are pregnant or planning to become pregnant. It can cause the development of male physical characteristics in a female fetus. You must use effective, non-hormonal contraception (such as condoms) while taking it.

Blood clots (Thromboembolism)

Danazol significantly increases the risk of serious blood clots. Seek immediate medical help if you experience sudden leg swelling, chest pain, or shortness of breath.

Liver disease

Danazol can cause serious liver damage and non-cancerous liver tumours. You will need regular blood tests to monitor your liver function while taking this medicine.

Severe infection, dehydration, or high alcohol intake

Stop taking metformin and seek urgent medical help if you develop symptoms of lactic acidosis, such as severe vomiting, stomach ache, muscle cramps, or deep, rapid breathing. This is a rare but serious emergency.

Contrast dye scans (e.g., CT or X-ray)

You must tell your doctor you take metformin if you are having a scan involving an injection of 'contrast dye'. You will usually need to stop taking metformin 48 hours before and after the procedure to prevent kidney damage.

Food and drink warnings

Alcohol

It is best to avoid or strictly limit alcohol while taking metformin. Drinking alcohol can increase the risk of a rare but serious condition called lactic acidosis (a build-up of lactic acid in the blood). It also increases the risk of low blood sugar (hypoglycaemia).

It is best to avoid or strictly limit alcohol while taking danazol. Combining danazol with alcohol can cause you to feel nauseous or short of breath (a disulfiram-like reaction). Additionally, both danazol and alcohol can put strain on your liver, and using them together increases the risk of liver damage.

Vitamin B12 absorption

Long-term use of metformin can prevent your body from absorbing enough vitamin B12 from your food. You may need to have your B12 levels checked by your doctor or take a supplement if you develop symptoms like extreme tiredness or a sore tongue.

Using other medicines

Taking multiple medicines? Our Medicines Interaction Checker helps you check whether your prescriptions, over-the-counter medicines, and supplements are safe to take together. Simply search for your medicines to see potential interactions and what to do about them.

Disclaimer

This information is for general educational purposes only and should not be relied upon as a substitute for professional medical advice. Always consult your GP, pharmacist, or another qualified healthcare professional before making decisions about your medications. Individual circumstances may vary, and only a healthcare professional who knows your medical history can provide personalised guidance.